It is known that such spheres may be manufactured by a number of casting or molding methods using molds specifically adapted in each case to the material used. Such known methods and the apparatus utilizing them have a number of disadvantages, chief among them being the fact that it is extremely difficult to eliminate the parting line on the final sphere, corresponding to the line on which the two halves of the mold close, and the protuberence left by the so-called sprue or entry port of the molten material. The accuracy of the resulting sphere is determined by the condition and the shape of the mold, which in turn are adversely effected by frequent use, quite apart from the difficulty in initially arriving at a perfect shape. Another method which is used particularly with glass spheres and which may also supplement the previously described method is to grind a large number of rough spheres in a rotating drum together with an abrasive powder. This method produces spheres with matt surfaces which are also relatively inaccurate and exhibit considerable differences between their major and minor diameters.